Onboard Wind Speed and Road Grade Measurements for Determination of Model Coefficients on Cycling

Different models for cycling power prediction have been presented and validated by different authors. The model validation processes have been performed in laboratory tests and field experimental tests. In field tests, different methods have been used, and in recent years, cycle-mounted power meters have been widely used for model validation and bicycle-cyclist set parameters determination. Field tests have been limited to the use of close spaces to avoid the high influence of external wind and to test in nearly flat surfaces. Although many studies have been carried out successfully in closed places, some advantages of the outdoor testing have not been exploited. This paper presents a methodology for performing outdoor tests while including the power delivered by the cyclist, the onboard measurement of wind speed and the accurate measurement of the road grade. The methodology seeks to determine the aerodynamic drag and rolling resistance coefficients based on experimental outdoor tests. A least squares method is used for identifying the model coefficients from the experimental data. A high correlation and significant similarity between the power measured and the power predicted by the model is found. These results suggest a good reliability of the wind speed measurement method and prove an improvement in the power prediction when including the onboard wind speed and road grade data. The coefficients found are in agreement with previous works presented in literature with similar bicycle-cyclist set characteristics.